Art of casting fiber articles



1933. E. HUFF ET AL I ART OF CASTING FIBER ARTICLES Filed June 19, 1930 Patented. Feb. 28, 1933 UNITED .STATESxPATEN'F OFFICE nmmsr nun, or mnwauxnn, AND mnanw xmnmc, or wrrmrrsn BAY, wraconsm, assrcnons 'ro mnmom LACE rerun comrm, or MILWAUKEE, wracousin, a coaroaa'rron. OF WISCONSIN AB! 0] CASTING FIBER ARTICLES a licat on, filed June 19,

.to provide a novel and im roved casting aparatus and method for t e manufacture of her-articles of a. form which may be characterizedas bulbous in that there is an 1nterior cavity of larger size than the neck of 1 the mold upon which the article is cast.

More particularly stated, it is our purpose to provide means for .the use upon a standard foraminous mold, or otherwise, of a porous body which may comprise a mold extension,

and which is preferably in the form of a split ring of felt or the like having sufficiently flexible characteristics so that 'upon com letion of the casting o eration the feltike body may be drawn rom the cast article (followin the withdrawal of the metallic portion 0' the mold, if such a mold portion is used). The advantages and details of the construction referred to will be more apparent in the light of the following disclosure.

In the drawing:

Figure 1 is afragmentary detail in section,

V. of a vat, and a diagrammatic illustration of the immersion therein of a mold fabricated in accordance with this invention and adapted for the casting of a'bulbous article.

Figure 2 is a' view similar to Fig. 1 but showing the deposit, on the surface of the composite mold, of the fiber particles suspended in the fluid of the vat.

Figure 3 is a diagrammatic illustration of the cast article and fibrous portion of the mold in section as they appear upon withdrawal of the core of the mold.

Figure 4 is a view in, a section similar to .40 that of Fig. 3, showing the withdrawal of the fibrous portion of the mold from the cast article.

Figure 5 is a detail view in section taken in the horizontal plane indicated at 5-5 in Like parts are identified by the same reference characters throughout the several views.

It has for a great many years been stand-' ard commercial practice to mold or cast apier-mach articles by immersing a foramlnous mold 111 8. vat containing a suitable 1930. Serial no. 402,218.

liquid such as water, in which particles of macerated paper are suspended, and by exhausting the contents of the foraminous mold by suction to cause the water of the vat to pass through the mold and deposit the paper particles upon its surface to any desired depth. In practice, however, this process has been definitely limited in its operation due to the difliculty and expense of providin and manipulatin any suitable form of col apsible mold en argement which would permit of the production of bulbous vases or other utensils,'the term bulbous being used to define any article having an interior cavity larger than the neck portion through whic the mold must be withdrawn.

In the practice of the present invention we' to the deposit of papier-mach on the surface of the mold.

'It will be noted that the foraminous mold 10 flares at. its upper end, whereas its lower end portion 14 tapers more gradually and is preferably 'aproximately cylindrical. In order to create the desired bulbous form of the completed article we prefer to employ upon the mold 10 a mold extension 15 which may conveniently be made of skived felt or (any other suitable porous body, including s onge rubber, cork, asbestos, and textiles. T e obj ect is merely to provide a porous mold extension which may becut or wound to the desired external contour and is sufliciently flexible to permit of its withdrawal through the neck of the proposed cast article. Felt has been found to be particularly suitable and may readily be carved or skived, to the desired con- 4 tour and made up in the form of a split ring having tapering overlapping ends, as shown in Fig. 5.

The form of a body of felt is less subject to. distortion and is more easily attained than the form of an ordinary foraminous metal mold. It is also very cheap, and while it may be used repeatedly it may also, in special cases, be allowedto remain in the casting where desired, and for this purpose a very cheap form of rough felt may be used. As an illustration we have shown a pad 16- of rough felt applied to the lower end of the foraminous metal mold member 10 to provide a hollow base for the completed cast article in which this pad 16 may be left for convenience. Obviously, it might also be withdrawn 1f desired,.and it will be understood that the disclosure in this respect is merely illustrative.

- The portions of the foraminous member or mold 10 which are covered by the felt or the like need not have the small openings which are characteristically found in the remaining wall of the mold member 10. Any size of ,exactly as if the intervening mold member 10 were eliminated.

It will also be obvious that where desired the felt or similar body used in the device, or a series of such bodies, may be used to cover the entire exposed surface of the foraminous member 10. For illustration, however, we

have chosen to show a mold which comprises ...1n part the foraminous member 10, and in part the felt body 15 within which the lower end portion 14 of the foraminous member 10 1s merely a core. It is because of the actual use in part, of the foraminous member 10 to define the' form of the cast article, that the foraminous member flares so widely at its up- ;per end portion.

The foraminous member 10, assembled, as above described upon the suction pipe 11 and bearing the porous mold extensions 15 and 16, 1s lowered into the vat 17 which is filled with -;water or other suitable liquid'at 18, in which the particles-19 of macerated paper are suspended. The vacuum applied through pipe 11 and hose 12 quickly sucks all the air from the mold apparatus, and water immediately commences to flow into the mold through the openings of the foraminous member 10 and thepores or interstices of the-felt or like fibrous bodies 15 and '16.

- While the holes in the foraminous mold are shown comparatively large for convenience of illustration, it will be understood that they are inpractice very small. In fact it is usual in the art to use a fine screen or gauze for the mold member, or as a cover therefor, so that as the water flows through. the mold its content of pa er, wood, leather or asbestos fiber, or other fi rous material will be deposited on the surface of the mold and mold extension.

When a deposit of aper or the like (other macerated materials than paper. may be used) has reached a required depth upon the composite mold, as shown in Fig. 2, the mold and the article cast thereon are removed unitarily from'the vat and, if the vat contains water or other liquid, a drying operation is desirable. The drying operation is mentioned conditionally for the reason that the process may-be practiced even in a body of gas instead of water, where the material to be deposited on the mold is sufliciently light with reference to the fluid supporting it, so that the fluid used may comprise a gas.

The core portion of the mold is now freed from the mold extension and from the cast article by connecting pipe 11 with a source of air under pressure instead of a source of partial vacuum. The compressed air blows the completed'article from the mold, and this method of freeing the foraminous portion of the mold from the article is preferred even where the shape of the core is such that the mold could be pulled therefrom. The air under pressure tends to force out of the small openings in the mold any fibrous or paper particles which are partially intruding there- 1n, and thus leaves the foraminous member clean for a succeeding mold operation.

The next step in the completion of the cast article consists in withdrawin therefrom the mold extension upon which as been depositedthe bulbous body of the article. This is done, as illustrated in Fig. 4, by simply inserting a hook through-the mouth of the cast article and pulling upon one of the overla ping free ends of the felt ring 15. The fe t ring readily opens up helically and is sufficiently flexible to pass readily through the mouth of the article. If the article is of such a shape that one ring will not ass readily through its mouth it will be obvious that a number of rings of short axial extent may be superimposed to build up the desired contour.

It is to be understood that although we have referred in this ap lication to the use of suction as a means or producing fluid 1 flow through the wall of the mold to deposit the suspended particles thereon, we are niindful of the fact that any means of establishing the necessary pressure differential may be used for the purposes of the present invention. We contemplatejhe use of a sealed yet 17 and a ram for placing high pressures on the surface of the fluid therein suflicient to force the fluid from the vat through the wall of'the mold, and to an overflow point in pipe'll. In so doing, the back pressure of the fluid in pipe 11, if that fluid be relatively heavy, as in the case of a liquid, will tend to create a very dense deposit of suspended matter on the wall of the mold. This slightly modified process therefore may be used where articles of high density and low porosity are required. It offers a way of preserving the naturally rou h texture of the pulp deposits which would be destroyed by the pressure of a female die member instead of the fluid pressure as suggested.

We claim: 7 1. Casting apparatus of the class described, comprising the combination with a dischar e pipe, of a porous body with the pores 0 which said pipe communicates, said ody having exposed surfaces of the desired contour of the article to be cast, characterized by a dimension reater than an opening in said article, a p lp container and means for establishing a pressure differential between said container and pipe whereby to deposit pulp on said porous body, said porous body being deformable sufliciently to permit its removal through said opening.

2. Casting apparatus of the class described,

V comprising the combination with a dis-- charge pipe and a hollow foraminous mem ber communicating therewith, of a orous body of desired contour characterize by a dimension in excess of an opening in an article to be cast thereon and applied to a portion 'of said foraminous member and constituting an extension of the surface thereof,

said body being deformable sufficiently to permit withdrawal thereof through said opening.

3. Casting apparatus of the class described, comprising the combination. with a hollow foraminous member having a dischar opening and of such form as to be wit drawable from feasting, of a highly porous mold extension of a form characterized by a dimension when applied to a ortion of said member in excesof the capacity of an open-,

ing in said casting and having its pores coin- Inunicating through a foraminous wall of said member with the interior thereof, said extension being sufliciently deformable for removal from said casting through said opening. i

4. Casting apparatus of the class described, comprising the combinatioh with a hollow foraminous member having a discharge opening and of such form as to be withdrawable from a casting, ofa highly porous mold extension applied to a portion of said member and having its pores communicating through v a foraminous wall of said member with the interior thereof, said mold extension com! prising a body of felted fiber, larger, when PP ied to said member, than an o nin in said casting, and sufliciently d'e orina 1e, when said member is withdrawn, to be re-. moved from said casting through said openm j Casting apparatus of the class described, comprising the combination with a hollow interior thereof, saidmold extension comprising a ring-like'body of feltof an external contour corresponding to the desired shape of the article cast thereon, of an effective size larger than an. opening in said casting and from which said foraminous member is retractible, said extension being sufiiciently deformable to be withdrawn from said casting throu h said opening.

6. gasting apparatus of the class described, comprising the combination with a hollow foraminous member provided with an exhaust passage and of which a portion constitutes a mold and another portion constitutes a core, ofa highly porous body detachably applied to the core portion of said foraminous member with its pores in communication through said member with the interior thereof and the exhaust passage, whereby said member and body together constitute a mold.

7. Casting apparatus of the classdescribed, comprising a tapered core member having an apertured wall and an exhaust port, of a felt body surrounding an apertured portion of said member and freely removable from the tapered end thereof, said body having an external contour corresponding to that of the article to be cast and communicating through its pores with the interior of said member.

- 8. Casting apparatus of the class described, comprising a hollow foraminous member provided with adischarge port, and a felt-like bod in the form of a split ring detachably app ied to a portion of said member having openings through which said felt communicates with the interior of said member.

9. Casting apparatus of the class described, comprising the combination with a hollow mold member provided with a wall having openings, of a plurality of preformed-felt bodies applied to the openings in said wall and adapted to constitute mold extensions ofsaid member. p

10. A casting process of the class described, comprising building up a mold with a removable porous body comprising an extension of the mold and of a size larger than an opening in anarticle cast thereon,,depositing material on the surface of the mold and mold extension, and "withdrawing themold from said body and the article cast thereon. a

11; A casting process of the class described,com,prising building up a mold with a removableporous body comprising an exdepositing material on the surface of the mold and mold extension, withdrawing the mold from said body and the article cast thereon, and subsequently .deformmg and withdrawing the body from the article through said opening.

12. A casting process of the class described, comprislng the immersion of a fibrous mass of predetermined contour in a fluid in which particles are suspended, creating a pressure differential between said fluid and an interior portion of said mass, circulate fluid through said mass and deposit szid suspended material on the surface there- 0 v 13. A casting process of the class described, comprising the shaping of a felt-like mass to desired contours and connecting a portion thereofto a discharge port while exposing other portions thereof to a fluid in which particles are suspended under pressures exceeding those in the port. 14. As a new article of manufacture, a mold member comprising a porous flexible body of substantial thickness having a normal annular form with free ends in substantial abutment.

15. As a new article of manufacture, a mold member comprising a flexible porous body of annular form and substantially uniform thickness throughout its circumferential extent in any given plane normal to its axis, the ends of said body being free and contiguous.

16. As a new article of manufacture, a mold member comprising a flexible porous body of annular form and substantially uni-- form thickness throughout its circumferential extent in any given plane normal to its axis, the ends of said body being free and contiguous in overlapping relation, said ends being of complementary form and tapering thickness whereby to overlap without varying the aforesaid uniformity of thickness of said body.

17. Gasti apparatus comprising the combination w ifii an highly porous flexible body removably wound on the support.

18. Casting apparatus comprising the comblnatlon with an apertured suppprt, of ahighly porous flexible body remove 1y wound on the support, said body having substantially uniform thickness in a given plane normal to the axis of the support and having an overlapping end engageable for the purpose of unwinding said body.

, ERNEST HUFF.

ANDREW KEIDING.

whereby to apertured support, of a 

